The invention relates to a method of simultaneously manufacturing multiple electrical connections between two elements each provided with metallizations, the contact pads of one element, which are destined to be electrically connected to those of the other element, being designed so that, when the elements are provided oppositely to each other in a given position, each contact pad supported by one of the elements is present opposite the corresponding contact pad of the other element, with a given quantity of an electrically conductive paste being provided on each contact pad of at least one of the two elements.
The invention is used in the electronic industry, for example, for the assembly of semiconductor elements. The connection of a semiconductor element on a substrate of a hybrid circuit or a comb of conductors may be done in a known manner by providing the semiconductor element on the substrate or the comb in such manner that their contact pads lie opposite to each other and by providing a given quantity of a conductive paste, generally an epoxy resin filled with silver or gold particles, between each contact pad of the semiconductor element and the corresponding one of the substrate or the comb, after which the paste is polymerized, for example by heating.
Such a method is known from British Pat. No. 1,525,148, which describes a bonding method for an integrated circuit on a substrate by means of a drop of a conductive glue on each contact pad of the integrated circuit. This patent specification further describes that with aluminum contact pads the aluminum oxide on said pads should previously be removed at least partly. Since the contact pads generally are of aluminum, this problem is very annoying. After a certain period of storage it is found that the oxide which had been removed has formed again, no doubt because either the glue did not seal or because it was self-oxidizing, or both. Of course this involves an interruption of the bond and the creation of a defect.
In order to avoid this inconvenience, the aluminum contact pads must be treated in one or more chemical, physical-chemical or electrochemical treatments in such manner that a metal or an alloy compatible with the conductive glue is deposited on the pads. The advantage of the bonding method, however, then is lost for the greater part because of the rejects which it involves, as well as the costs of the treatments.